title: [Mitral valve replacement by Starr-Edwards and Björk-Shiley prostheses, long term results and statistical analysis of some risk factors (author's transl)].
abstract: 304 patients have been studied between 1972 and 1977 after mitral valve replacement. 133 patients had a Starr-Edwards prosthesis and 171 patients had a Björk-Shiley prosthesis; both groups presented similar risk factors. The follow-up varied between a 6 months and a 72 months period for both types of prosthesis with a mean period of 3.2 years. The statistical results were based on the cluster system and he outcomes helped us to realise curves of homogeneous groups of patients who underwent mitral valve replacement with Starr and Björd prosthesis. One observed that 4 years from date of surgery the survival percentage is 84% for those patients with the Starr prosthesis and 78% for Björk prosthesis; with regards to the log rank test this difference is insignificant. Considering the probability of embolism one observed a percentage of 10% of the patients with the Björk prosthesis and of 18% with the Starr prosthesis; this difference is insignificant from the statistical point of view. The cluster analysis of the considered parameters (age, type of valve defect, NYHA class, duration of symptoms before surgery, C/T, size of left atrium) did not evince real and proper risk factors at least not such to condition the long term results. The only observed relationship is the one between the major incidence of embolism and great left atrium. One may conclude that not exist differences in long term results between both prostheses when placed in mitral valve.
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006350:Heart Valve Prosthesis; D006801:Humans; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D012306:Risk; D013223:Statistics as Topic
vernacular_title: Sostituzione valvolare mitralica con protesi di Starr-Edwards e Björk-Shiley. Risultati a distanza e analisi statistica di alcuni fattori di rischio.